Industrial mixers are used to mix bulk material, typically powdered bulk material which are used to form a mixture of synthetic granulates, as well as in the dye industry. These mixing machines have a mixing head which is mounted pivotably relative to a frame, and which also serves to close up a container containing the material to be mixed. The container is connected to the mixing head for the purpose of the mixing the material. A closed mixing receptacle is formed from the mixing head and the container containing the mix by connecting the container to the mixing head. The mixing head has one or several connecting elements for the purpose of connecting the container to the mixing head, for example, an encircling flange. This mixer is also operated as a container-mixer since in these mixing machines a container containing the mix is connected to the mixing head. The mixing head is disposed pivotably relative to the frame of the mixing machine. In operation the mix is disposed in an overhead position relative to the mixing head, with the mixing head is lowermost and the connected container is uppermost.
Such previously known container-mixers have a device for producing a mix stream. An axially disposed tool in the mixing head produces the mix stream, which is rotary-driven by a motor. Such a tool has several blades projecting radially from the drive shaft forming a type of propeller. One such container-mixer is known from EP 0 225 495 A2. There may be several such tools are disposed on the drive shaft. In prior art mixers, this tool serves as a mixing tool and during operation of the mixer therewith produces a mix clump with the mix contained in the mixing receptacle. The mix is flung upward in an axial area by means of the mix tool or tools and is then deflected radially outward by gravity on the inside of the receptacle back to the tool. In the previously described mixing tool, a mix stream is produced in which contains the whole mix found in the mixing receptacle. The mixing process results from the acceleration of the mix at the mixing tool or tools and the turbulence in the mix stream.
A second motor-driven mixing tool is disposed in the wall section of the receptacle interacting radially in applications in which more energy is to be introduced into the mix by the mixing tools. The second motor-driven mixing tool has a higher rpm relative to the rotation speed of tools used to produce the mix clump. Several such radially disposed mixing tools can be provided. The at least one mixing tool provides further energy input into the mix clump produced by the feed tool thereby improving particle dispersion and supporting the mixing process. The formation of a high-energy mix clump is required for the mixing process in the design of such mixing machines. The particles in the mix clump are supplied to each mix at a rate of about 20 m/sec with these previously known mixing machines.
With industrial mixing machines, an effort is made to reach the desired thorough mixing in the shortest time possible. However, when thorough mixing is possible in a shorter time with higher tool rotations than with more slowly rotating tools, care is taken to prevent too much heat from being introduced into the material to be mixed. This must be carefully watched with a mix of synthetic granulates since the individual granulate particles can stick to one another and/or stick to the tool if too high of temperature is reached. Therefore, in the previously described mixing machines, the mixing time is limited to prevent the first and the second mixing tools from getting very hot during operation and preventing the skin friction of the particles on the inside of the receptacle heating up the mix.
The foregoing example of the related art and limitations related therewith are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings.